Today, the operation of many hydraulic and pneumatic systems in vehicles, heavy equipment, or other applications is controlled by control systems employing Controller Area Networks (CANs) having centralized or decentralized architectures. In a centralized Controller Area Network (CAN) architecture, a central controller of a hydraulic or pneumatic system presents information to and receives input information from an operator via a human machine interface (HMI) device. The central controller also receives input information in the form of data collected by various sensors located in strategic locations of the system. Acting under the control of software executed by the central controller and using the input information, the central controller communicates appropriate analog signals via the Controller Area Network (CAN) to solenoids, switches, and similar devices that are connected to or integrated with controlled system components such as valves, pumps, and other controlled components. For example, after receiving appropriate input information such as data representative of joystick movement, a central controller may communicate analog signals to a solenoid of a valve causing operation of the valve as required to operate a single service such as extending or retracting a hydraulic cylinder or causing rotation of a hydraulic motor.
In a centralized Controller Area Network (CAN) architecture, an extensive amount of wiring is necessary to electrically connect the central controller with human machine interface (HMI) devices, sensors, and controlled components. The cost of such wiring depends on a number of factors (including, at least, the lengths of the wires, required wire protection, and routing difficulty). Also, because the wiring is extensive, it is prone to wiring mistakes (such as, but not limited to, connecting wires to the wrong components) and provides a large number of possible locations for failures. Additionally, since the central controller and controlled components are, typically, not assembled and tested together until final assembly on/in the machine, device, or system in/with which they are used, final calibrations and adjustments (including, without limitation, establishing jump-to currents, and setting limits and shaping characteristics) must be made during final assembly of the hydraulic or pneumatic system.
In contrast to a centralized Controller Area Network (CAN) architecture, system control and communication capabilities are distributed and are located at controlled components in a decentralized Controller Area Network (CAN) architecture. The controlled components each have a local controller which can communicate on the Controller Area Network (CAN). Control software is executed by the local controller and signals are output from the local controller to solenoids, switches, and similar devices of a controlled component to cause appropriate operation of such devices and, hence, of the controlled component. Because the control software is executed locally, calibrations may be performed before final assembly of the hydraulic systems of which the controlled components are a part, thereby making the controlled components “ready-to-run” and requiring little, if any, post-assembly calibrations. Also, due to the co-location of the local controllers and proximity to local sensors, the controlled components are, generally, capable of greater software configurability and wiring is minimized, thereby significantly reducing wiring costs and reducing the number of locations for potential failures to occur. While a decentralized Controller Area Network (CAN) architecture provides such benefits, use of the architecture suffers from the cost associated with each controlled component having its own electronics including a printed circuit board assembly configured with a digital signal processor, Controller Area Network (CAN) communication hardware, current drivers, and, possibly, sensors.
Therefore, there is a need in the industry for a network architecture for controlling the operation of hydraulic, pneumatic, and other systems that provides enhanced local control, minimal calibration, and reduced wiring similar to a decentralized Controller Area Network (CAN) architecture, that minimizes the cost of controlled components similar to a centralized Controller Area Network (CAN) architecture, and that addresses these and other problems, issues, deficiencies, or shortcomings of present Controller Area Network (CAN) architectures.